Electrical device



NOV. 1966 c. w WILLIAMS 3,289,143

ELEGTRIGAL DEVICE Filed Dec. 23, 1964 United States Patent C) 3,289,143 ELECTRICAL DEVICE Charles W. Williams, 222 Greenview, Mundelein, Ill. Filed Dec. 23, 1964, Ser. No. 420,545 Claims. (Cl. 339-445) This invention relates to an electrical device and particularly relates to a spring contact adaptor for use in connection with electric light bulbs which fit into sockets.

In such devices as taillights of an automobile and other similar uses of electric light bulbs, the bayonet type base and socket for mounting the light bulb is oftentimes employed, and it has been experienced that when such sockets have been in use for a considerable period of time, there is some deterioration and corrosion which occurs. In the sockets for such bulbs, the bottom central terminal in the socket for engaging the corresponding central terminal of the light bulb base, is conventionally spring mounted so as to be urged resiliently outwardly or upwardly against the base contact of the bulb. After a period of usage, the spring which urges the contact outwardly, sometimes becomes weaker, and possibly due to corrosion and other deterioration, as well as the weakening of the spring, difiiculty is experienced, when replacing the bulb, in obtaining a sound electrical connection between the central terminal of the socket and the base contact of the bulb, and therefore the lighting of the bulb is uncertain and in some cases intermittent, and in some cases the bulb merely burns dimly because a good electrical contact is not made.

This condition has caused many taillight assemblies to be completely replaced at a substantial expense to the owner of the vehicle. Oftentimes the owner of the vehicle thinks that he merely needs a new light bulb and when a garage tells the owner that he needs a whole new light assembly, a bad personaland business relationship often times results because the owner thinks that the repair expense is unwarranted in view of the apparent simple nature of the repair thought to be needed.

With these comments in mind, it is to the elimination of these and other disadvantages to which the present invention is directed, along with the inclusions therein of other novel and desirable features.

An object of my invention is to provide a spring contact adaptor of simple and inexpensive construction and operation for use in connection with replacement bulbs being applied to a corresponding electric light bulb socket.

Another object of my invention is to provide a new and novel spring contact adaptor for ready and easy application between the base terminal of an electric light bulb and the central socket terminal from which power is supplied to the electric light bulb so as to provide a sound electrical connection, in spite of some deterioration of certain portions of the bulb socket. Another object of my invention is to provide a novel and improved spring contact adaptor which is readily and easily applicable to the base of a replacement light bulb as it is being prepared for insertion into the bulb socket so as to provide for increased pressure at the contact between the base terminal of the bulb and the central terminal of the socket to compensate for any deterioration or spring weakening which has occurred in the socket over a period of time.

These and other objects and advantages of this invention will more fully appear from the following description made in connection with the accompanying drawings, wherein like reference characters refer to the same or similar parts throughout the several views, and in which:

FIG. 1 is an elevation view of a light bulb with the present invention applied thereto and shown in section together with a typical socket which is also shown in section and illustrated for holding the bulb;

FIG. 2 is a greatly enlarged longitudinal section of the present invention before application to the bulb;

FIG. 3 is a top plan view of the invention illustrated in FIG. 2 with a portion thereof broken away for clarity of detail;

FIG. 4 is a bottom plan view of the present invention;

FIG. 5 is a bottom end view of the base of a typical light bulb which employs two different filaments and therefore has two separate terminal contacts;

FIG. 6 is a detail elevation view of a portion of the base illustrated in FIG. 5;

FIG. 7 is an elevation view partly broken away and shown in section and illustrating a modified form of the invention;

FIG. 8 is an end elevation view of the form of the invention illustrated in FIG. 7;

FIG. 9 is a top plan view of the form of the invention illustrated in FIG. 7 and illustrated in a condition wherein the peel-off strip is partly removed;

FIG. 10 is a bottom plan view of the form of the invention shown in FIG. 7.

The form of the invention illustrated in FIGS. 1-4 is applicable to a bulb 10 of the type with only a single filament 11 and therefore the-base 12 of the bulb has only one base terminal 13 in the central portion of the end 14 of the base. The base terminal 13 is constructed of some type of metal which is conventionally surrounded by some form of insulator so as to insulate the terminal 13 from the base 12 which serves as another contact connecting one side of the filament 11 to the bulb socket 15 or to ground of a vehicle. Such a socket 15 is conventionally provided with an insulative bottom portion 16 which may carry a metallic grommet 17 which secures and electrically connects to a coil spring 18. The upper end of spring 18 mounts an insulator washer or plate 19 which carries the socket terminal 20 for normally engaging the bulb terminal 13. The spring 18 is in electrical contact with the terminal 20 so as to convey electricity and power to the bulb from the grommet 18 and through the terminal 20 to the terminal 13.

The grommet 17 may have a solder connection to a conductor or a wire 21 for conveying power from the electrical system of a vehicle to the bulb filament 11, and of course the conductor will be provided with suitable insulation 22.

Of course, the socket 15 may be mounted in any of a plurality of manners such as by mertallic bracket 23 which may be suitably connected to the frame of the vehicle or to the body thereof.

The present invention comprises an insulator disc 30 constructed of any suitable insulative material such as cardboard or plastic. The insulative disc 30 is generally circular in shape as seen in FIGS. 3 and 4 and has a recessed central portion 31 so that the central portion of the disc is spaced below the upper face 32 thereof. The upper face 32 has a layer 33 of pressure sensitive adhesive thereon, and a peel-01f strip or cover 34 is provided over the adhesive 33 to protect the adhesive until the disc 30 is to be used. The annular rim portion 35 of the disc 30 is substantially the same diameter as the end 14 of the bulb base 12 so that the disc 30 may be applied unto the end of the base 12.

The disc 30 is provided with a slot opening 36 in the central portion 31 thereof; and a substantially U-shaped leaf spring contact 37 has its juxtaposed upper and lower ends 38 and 39 respectively disposed above and below the central portion of the disc 30 and has the central portion thereof extending through the slot opening 36.

When the spring contact adaptor 29 is to be used, the peel-oif strip 34 is removed and the upper face with the adhesive thereon is pressed firmly against the base 12 of the bulb. The bulb is thereupon inserted into the socket 15, and the bayonet pins are properly located in the bayonet slots so that the bulb It) is properly held in the socket. As the base 12 moves downwardly into the socket 15, the spring contact adapter 29 is carried therewith and the lower end 39 of the spring contact 37 engages and bears downwardly against the socket terminal 20. As the base 12 of the bulb progresses into its conventional seated position, the spring contact 37 will be urged by the socket terminal 20 upwardly against the base terminal 13 so that the leaf spring contact 37 is actually flexed. The spring 18 in the socket is conventionally compressed as the bulb is seated in the socket and the spring contact adaptor 29 produces sufficient additional pressure against the base terminal 13 and against the socket terminal 29 as to provide a very sound and stable electrical connection between the socket terminal 2t) and the base terminal 13. This additional pressure minimizes the effects of general deterioration, of the socket including weakening of spring 18. It Will therefore be understood that by simply applying a spring contact adaptor 29 to the bulb 10, the socket 15 which may be fairly old and well used may be continued in service without making replacement necessary.

The base of a double filament bulb is illustrated by base 40. The base 40 has a pair of base contacts and terminals 41 on the lower end 42 thereof. The base contacts 41 are surrounded by a typical insulating disc or washer 40a which is conventional to the bases of such bulbs.

The form of the invention illustrated in FIGS. 7-10 comprises an insulative disc 43 constructed of such inexpensive material as cardboard or substantially rigid plastic, and in this form of the invention, the disc 43 has a diametric central portion 44 which is recessed below the upper face 45 of the disc which has a quantity of pressure sensitive adhesive 46 thereon to facilitate the application of the disc 43 to the base 40 of the dual filament bulb.

The disc 43 is provided with a peel-off strip or cover 47 which is shown in FIG. 9 to be partly peeled off and which normally performs the function of protecting the adhesive 46 until such time as it is desired to apply the disc to a bulb.

The diametric central portion 44 of the disc is provided with a pair of slot openings 48 adjacent each other and which respectively receive the central portions 49 of leaf spring contacts 50 and 51, the upper and lower end portions 52 and 53 of which bear upwardly against the base terminals 41 of the bulb and against the socket terminals which are correspondingly positioned in the socket.

In this form of the invention as well as in the other form, the leaf spring contacts apply additional pressure against the bulb terminals as to make a very sound and stable electrical connection which often times eliminates the need for replacement of the socket assembly.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the various parts without departing from the scope of my invention.

What is claimed is:

1. A spring contact adaptor for providing a sound electrical connection between the base terminal of a light bulb and the corresponding socket terminal,

comprising an insulator disc having an upper face with adhesive thereon to engage and adhere to the end of such a light bulb base to be carried by the base into the socket, said disc having a central portion recessed below said upper face, and said disc having an opening therethrough,

and a U-shaped leaf spring contact having opposite end portions respectively disposed above and below said disc and also having a central portion in the opening of said disc, said opposite end portions bearing upwardly and downwardly against the base terminal of the bulb and the socket terminal, said spring contact flexing to apply pressure against said terminal. a

2. A spring contact adaptor for providing a sound electrical connection between the base terminal of a light bulb and the corresponding socket terminal,

comprising an insulator disc having an upper face with adhesive thereon to engage and adhere to the end of such a light bulb base to be carried by the base into the socket, said disc having a central portion recessed below said upper face, said disc having an opening therethrough,

and an elongate spring contact extending through the opening in said disc and having upper and lower contact ends above and below the disc and resiliently movable with respect to each other to apply pressure against the base terminal of the bulb and the socket terminal.

3. A spring contact adaptor for providing a sound electrical connection between the base terminal of a light bulb and the corresponding socket terminal,

comprising an insulator disc having an annular upper face with adhesive thereon to engage and adhere to the end of such a light bulb base to be carried by the base into the socket, said disc having a circular central portion recessed below said upper face, and said disc having an opening therethrough in said circular central portion,

and an elongate spring contact extending through the opening in said disc and having upper and lower contact ends above and below the disc and resiliently movable with respect to each other to apply pressure against the base terminal of the bulb and the socket terminal.

4. A spring contact adaptor for providing a sound electrical connection between the base terminal of a light bulb and the corresponding socket terminal,

comprising an insulator disc having an upper face with adhesive thereon to engage and adhere to the end of such a light bulb base to be carried by the base into the socket, said disc having a diametric portion recessed below said upper face, and said disc having an opening in said central portion,

and an elongate Spring contact extending through the opening in said disc and having upper and lower contact ends above and below the disc and resiliently movable with respect to each other to apply pressure against the base terminal of the bulb and the socket terminal.

5. A spring contact adaptor for providing sound electrical connections between the side-by-side base terminals of a double filament light bulb and the corresponding side-by-side socket terminals,

comprising an insulator disc having an upper face with adhesive thereon to engage and adhere to the end of such a light bulb base to be carried by the base into the socket, said disc having a diametric central portion recessed below said upper face, said disc having a pair of spaced openings in said diametric central portion,

and a pair of elongate spring contacts each respectively extending through a respective opening in said disc and having upper and lower contact ends above and below the disc and resiliently movable with respect to each other to apply pressure against the base terminals of the bulb and the socket terminals.

References Cited by the Examiner UNITED STATES PATENTS 1,978,116 10/1934 Roper 339188 X 2,747,168 5/1956 Arena 339-176 2,759,160 8/1956 Kelley 339-12 2,788,504 4/1957 Hertel 339-31 X BOBBY R. GAY, Primary Examiner. W. D. MILLER, Assistant Examiner. 

1. A SPRING CONTACT ADAPTOR FOR PROVIDING A SOUND ELECTRICAL CONNECTION BETWEEN THE BASE TERMINAL OF A LIGHT BULB AND THE CORRESPONDING SOCKET TERMINAL, COMPRISING AN INSULATOR DISC HAVING AN UPPER FACE WITH ADHESIVE THEREON TO ENGAGE AND ADHERE TO THE END OF SUCH A LIGHT BULB BASE TO BE CARRED BY THE BASE INTO THE SOCKET, SAID DISC HAVING A CENTRAL PORTION RECESSED BELOW SAID UPPER FACE, AND SAID DISC HAVING AN OPENING THERETHROUGH, AND A U-SHAPED LEAF SPRING CONTACT HAVING OPPOSITE END PORTIONS RESPECTIVELY DISPOSED ABOVE AND BELOW SAID DISC AND ALSO HAVING A CENTRAL PORTION IN THE OPENING OF SAID DISC, SAID OPPOSITE END PORTIONS BEARING UPWARDLY AND DOWNWARDLY AGAINST THE BASE TERMINAL OF THE BULB AND THE SOCKET TERMINAL, SAID SPRING CONTACT FLEXING TO APPLY PRESSURE AGAINST SAID TERMINAL. 